BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method of encoding a carrier signal within a video
signal presented by a digital display device, and more particularly to a method for
modulating carrier signals in a video signal, presenting the video signals on a digital
display device, receiving the video signals on a detector or a combo user device,
detecting the carrier signal in the video signal, and providing the detector or combo
user device with a notification of a signal presence or a signal absence of the carrier
signal in the video signal.
[0002] Users of these hand-held devices selectively receive notification of the signal absence
or signal presence of carrier signals for purposes including enjoyment, promotion,
transfer of information, data collection, commercial verification, security, education,
and transactions or verifications at points of sale, as well as other commercial,
personal, entertainment, or amusement purposes collectively referred to herein as
"promotional opportunities".
[0003] Various methods exist in the art for transmitting a carrier (or subcarrier) signal
along with video signals, wherein the carrier signal is used for a variety of signaling
purposes. Several of these methods transmit the carrier signals, such as in the form
of auxiliary data, in the video signals by replacing active portions of the video
signal with auxiliary data, such that users who view the video signal on their display
devices (e.g., televisions) will see the effect of the carrier signal in the form
of an icon, dot or other visual image or disturbance in the picture. Other methods
transmit carrier signals in non-viewable scan lines of the video signal, such as in
the vertical blanking interval (VBI). However, these scan lines may already contain
other carrier signals such as signals that represent cueing information, timing information
or closed captioning information and are prone to being stripped by programming operators
prior to broadcast.
[0004] Another method for transmitting a carrier signal in video signals is described in
U.S. Patent 4,807,031 to Broughton et al. ("Broughton") entitled "Interactive Video
Method and Apparatus", which relates generally to in-band video broadcasting of commands
and other encoded information to interactive devices and is incorporated by reference
herein. The invention described therein relates generally to interactive educational
and entertainment systems, and is described in one embodiment in the context of television
program control of toys located where there is a television receiver, as within a
residence.
[0005] To encode control data, Broughton discloses a novel method of luminance or chrominance
modulation of a video signal that creates a composite video signal, wherein the video
signal is modulated with control data. The novel modulation method alternately raises
and lowers the luminance/chrominance of paired adjacent horizontal scan lines to create
a video subcarrier that contains the control data.
[0006] In Broughton, the video signal is not being replaced with other data, nor is the
data being added as a separate signal along with the video signal. Rather, the video
signal itself is modulated to carry the control data. Therefore, the control data
is a part of, or contained within, the video signal and yet is imperceptible to the
human eye. The encoding method also includes preview and remove circuitry to ensure
suitability or the signal presence of data encoding and removal of data encoding,
respectively.
[0007] The control data is transmitted either by television broadcast means, or by pre-recorded
video players that are connected to a video display. The control data is then received
by the video display where at least one video field of the video display is modulated
by control data. The control data is then detected with either opto-electronic or
radio frequency (RF) detection means that discriminate between the program material
and the control data to detect the control data. The detected control data is further
reproduced so that the control data can be used with an interactive device.
[0008] Improvements on the method of modulation described in Broughton are described in
U.S. Patent 6,094,228 to Ciardullo et al. and U.S. Patent 6,229,572 to Ciardullo et
al. (referred to collectively herein as "Ciardullo"). Both Ciardullo patents describe
improved methods of modulation wherein the auxiliary data is inserted on the visual
portion of a video signal by changing the luminance of paired scan lines in opposite
directions. Instead of raising and lowering the intensity on the whole line as in
Broughton, Ciardullo uses pseudo noise sequences to raise and lower the intensity
on portions of a first line, where the line paired to the first line is modulated
with the inverse pseudo noise sequences. Ciardullo thereby allows larger amounts of
auxiliary data to be modulated in the video signal by use of the pseudo noise sequences.
Broughton and Ciardullo, which are owned by the assignee of the present invention,
are incorporated by reference herein.
[0009] Prior efforts by the assignee of the present patent application also include United
States Utility Patent Application entitled "Interactive Optical Cards and Other Hand-Held
Devices with Increased Connectivity", Serial No. 09/489,373, filed January 21, 2000
by Edward J. Koplar and Daniel A. Ciardullo (referred to hereinafter as "Koplar I"),
which is incorporated by reference herein. Koplar I relates to various hand-held device
embodiments and methods of use by receiving auxiliary data (i.e., control data) from
a signal source and providing the user of the hand-held device with various promotional
opportunities, such as interactive advertising and gaming, as a result of receiving
the auxiliary data.
[0010] Another patent application by the assignees of the present invention is United States
Utility Patent Application entitled "Universal Methods and Device for Hand-Held Promotional
Opportunities", Serial No. 09/829,223, filed April 9, 2001 by Edward J. Koplar, Daniel
A. Ciardullo, James G. Withers and Christopher E. Chupp (referred to hereinafter as
"Koplar II"), which is incorporated by reference herein. Koplar II describes additional
methods of providing auxiliary data to hand-held devices for the purpose of providing
a user of the hand-held device with promotional opportunities, as well as apparatuses
for use with same.
[0011] Yet another patent application by the assignees of the present invention is United
States Utility Patent Application entitled "RBDS Method and Device for Processing
Promotional Opportunities", Serial No. 10/126770, filed on April 19, 2002 by James
G. Withers and Alan G. Maltagliati (referred to hereinafter as "Withers"), which is
incorporated by reference herein. Withers describes further improvements to Koplar
I and Koplar II including the transmission of auxiliary data to a hand-held device
by use of the RBDS system.
[0012] Still another patent application by the assignees of the present invention is United
States Utility Patent Application entitled "Method and Apparatus for Modulating a
Video Signal With Data", Serial No. 10/676,940, filed on October 1, 2003 by Yousri
Barsoum, Alan G. Maltagliati, Daniel A. Ciardullo and Christopher E. Chupp (the application
being herein termed "Barsoum"), which is incorporated by reference herein. Barsoum
describes the use of a memory card coupled to a slotted hand-held device for receiving
video signals by use of the memory card, transmitting the signals from the card to
the slotted hand-held device, decoding auxiliary data from the video signals on the
slotted hand-held device and providing the user of the slotted hand-held device with
a benefit from the reception of the auxiliary data. Barsoum also describes a method
of improving the reliability and speed of the transmission and reception of auxiliary
data by storing data in video frames split into multiple fields and encoding complementary
data bits in each field.
[0013] The Broughton method of encoding auxiliary data in a video signal and its improvements
were generally intended for use with analog display devices. The Broughton method
of encoding auxiliary data in the active portion of analog video signals relies on
NTSC's interlaced scanning process during video signal transmission. At the display
device (e.g., signal source), a video signal is split into two sequentially transmitted
images referred to as fields. The display device scans 262.5 of the horizontal lines
left to right and from top to bottom by skipping every other line, thus completing
the scan of a first field, and then retracing to the top of the image and scanning
the remaining 262.5 lines, for a second field. Both fields are reassembled by interlacing
them at the display device to construct one complete frame. Each field (i.e., half-frame)
screen scan takes approximately 1/60 of a second; a complete frame is scanned every
1/30 second.
[0014] An analog display device operates by use of a very fine pitch electron beam which
strikes phosphors coating on an internal face of the cathode ray tube (CRT). The phosphors
emit light of intensity which is a function of the intensity of the beam striking
it. A period of 1/60 second is required for the electron beam to completely scan down
the CRT face to display a field of the image. During the following 1/60 second, the
interlaced field is scanned, and a complete frame of video is then visible on the
analog display device. The phosphors coating on the face of the tube is chemically
treated to retain its light emitting properties for a short duration. Thus, the first
area of the scanned picture begins to fade just as the electron beam retraces (i.e.,
during the vertical retrace) to the top of the screen to refresh it. Since the electron
beam covers 525 lines 30 times per second, a total of 15,750 lines per second is viewed
each second. Analog video signal transmissions employ a variable wave form; digital
transmissions comprise pulse-form which signals transmission varies between different
levels such as on and off to represent digital ones and zeroes.
[0015] Digital display devices operate in a different manner than analog display devices,
as they do not have CRTs or any type of electron beam. Whereas the phosphors-coated
face of a CRT in an analog display device is passive (i.e., it merely emits light
in direct correlation to the intensity of the electron beam that strikes it), a plasma
or LCD digital display device is comprised of pixels (i.e., active picture elements).
The pixels may be small semiconducting devices that can be turned on and off at will,
one at a time, or simultaneously, in place of the CRT. LCD, digital light projector
(DLP), flat-panel, plasma and other digital display devices are collectively referred
to herein as "digital display devices".
[0016] The digital television standards in the United States allow several different broadcast
formats, including:
- 480i - The picture is 704x480 pixels, sent at 60 interlaced frames per second (30
complete frames per second);
- 480p - The picture is 704x480 pixels, sent at 60 complete frames per second;
- 720p - The picture is 1280x720 pixels, sent at 60 complete frames per second;
- 1080i - The picture is 1920x1080 pixels, sent at 60 interlaced frames per second (30
complete frames per second); and
- 1080p - The picture is 1920x1080 pixels, sent at 60 complete frames per second.
(The "p" and "i" designations stand for "progressive" and "interlaced." In a progressive
format, the full picture updates every sixtieth of a second. In an interlaced format,
half of the picture updates every sixtieth of a second.)
[0017] Digital display devices store each frame of a video signal and each frame is displayed
as a whole picture on the digital display device. Thirty frames (i.e., pictures) are
transmitted per second, or thirty pictures are transmitted and sixty are displayed
as each picture is displayed twice. Thus, the resulting frame frequency is either
30 Hertz or 60 Hertz. The present invention makes use of this frequency, which is
the refresh rate of the display at 60 frames per second.
[0018] In CRT operation, each scan line occupies a constant amount of time to display on
the CRT. The time to scan each line is 63.5 microseconds, so that 15,750 lines are
scanned each second, i.e., with a frequency of 15,750 Hertz. Using an optical detection
device such as a photodiode, this frequency can be detected as described in Broughton.
Broughton subtly changes the amplitude of alternate lines of video which also may
be detect by the photodiode at a half scan line rate of 7875 Hertz (roughly 8000 Hertz)
signal. In operating a typical digital display device, neither of these frequencies
exist since the entire picture may be displayed at once rather than line by line.
However, the frame display rate of 30 Hertz is constant both in analog (e.g., CRT)
and digital displays (e.g., flat panel).
[0019] For purposes of the present invention, the term "hand-held device" means an interactive
device of portable character, preferably of hand-held type that may be carried in
the palm by a user, or between fingers of the user, or is otherwise intended to be
easily grasped and handled manually by the user. Smart cards, mobile phones, personal
digital assistants (PDA's), games devices and similar hand-held devices with or without
capability for memory cards that are capable of participating with the promotional
opportunities described in the present invention and are collectively referred to
herein as "hand-held devices" of the present invention.
[0020] The term "computer" is also used herein in its broadest possible sense, and may include
without limitation a laptop, compact or personal computer, mobile phone, gaming device,
personal digital assistant (PDA), or other computer-like device.
SUMMARY OF THE INVENTION
[0021] The present invention discloses a novel method of encoding carrier signals in video
signals to be presented on a digital display device and a detector for receiving the
video signal and detecting the carrier signal, and more particularly to a method of
modulating a video signal with a carrier signal, presenting the modulated video signal
on a digital display device, receiving the modulated video signal on a detector, detecting
the carrier signal from the modulated video signals, and providing a benefit from
the detection of the carrier signal.
[0022] A video program in the form of video signal is transmitted from a signal source to
an encoder. An Operator interacts with the encoder to control its operation. A carrier
signal is selectively encoded in the video signal by the encoder over one or more
sets of two frames of the video signal for a time interval by the operator for signaling
purposes, such as to signal signal presences and signal absences over desired intervals
in the video signal.
[0023] Upon modulating the video signal, the encoder outputs a modulated video signal comprised
of the video signal and the carrier signal. The Modulated video signal is then provided
to a broadcast source for dissemination or distribution to one or more end-users who
view the video program. The broadcast source provides the modulated video signal to
a decoder, which passes the modulated video signal through to the digital display
device unaltered.
[0024] The decoder uses the modulated video signal to determine whether a carrier signal
is present in the modulated video signal over a specified or predetermined time interval
so as to trigger a signal absence (e.g., carrier signal not present) or signal presences
(e.g., carrier signal present) of the carrier signal. When the carrier signal is present,
the decoder provides notification of the signal presence of the carrier signal to
a signaled device by transmission of the transmission signal. When the carrier signal
is not present, the decoder transmits a signal absence. Preferably, the signaled device
and the decoder are combined together in a combo user device such as a hand-held device
that considers the signal presence to be a data bit of "1" and the signal absence
a data bit of "0" and uses the data bits to provide promotional opportunities to its
user.
[0025] The preferred encoding method of the present invention is by generating the video
signal in real time or pre-recorded at the signal source. Thereafter, the video signal
is provided to the encoder from the signal source. The encoder then stores the chrominance
value of the digitized video signal in storage. The Operator then directs the encoder
through various indications received by the encoder through the carrier signal presence
on the inclusion of signal presences and signal absences in selected pairs of frames
of the video signal. Upon receipt of the indications from the operator, the encoder
first determines the timing of where the fields of the frames of the video signal
start by use of the vertical synchronization signal. The Encoder thereafter determines
whether to encode a signal absence or signal presence based on the indication received
through the carrier signal presence. If the encoder does not receive any instructions
via the carrier signal presence to modify the video signal, the encoder encodes signal
absences. However, when the encoder seeks to encode a signal presence, the encoder
modifies the luminance of two frames of the video signal so as to modulate the video
signal.
[0026] In an alternate embodiment, the encoder modulates a constant 15 Hertz signal within
every frame of the video signal or an encoded portion thereof. The encoder encodes
a signal presence by slightly increasing the amplitude of the 15 Hertz signal within
a frame, and encodes a signal absence by slightly decreasing the amplitude of the
15 Hertz signal within a frame.
[0027] In a further embodiment, the encoder encodes one or more bits of auxiliary data per
two consecutive frames by adjusting the amplitude to predetermined levels representing
one or more bits. During decode, the amplitude is measured based on predetermined
levels and relates to one or more bits.
[0028] To detect carrier signals by use of the present invention, in the preferred embodiment
preferably a detector in hand-held form is outfitted with a photodetector used to
visually detect overall light energy emanating from the digital display device. A
hand-held device typically is outfitted with a photodetector, microcontroller, memory
and other circuitry to receive and process the modulated video signal. The microcontroller
and circuitry of the hand-held device filter all frequencies over 60 Hertz. Thereafter,
the remaining signal present is a low frequency amplitude modulated signal.
[0029] When encoding carrier signals as auxiliary data, a ones-complement scheme (matching
a stream of alternating ones and zeros against each other) is preferably used to detect
packet start and CRC checking is used for error correction. The final result is a
15 bit/sec data stream (depending upon the embodiment and intensity chosen) that can
be detected by a hand-held device with an optical detector similar in some respects
to those described in Koplar I and Koplar II.
[0030] In making use of the present invention, signals are received, detected, and reproduced
by the hand-held devices for various promotional opportunities including: enjoyment;
promotion; coupon or prize validation; advertising by sponsors; advertising verification
and polling; transfer of information; data collection; commercial verification; security
and access; education; game playing; transactions, verifications, or redemption by
sponsoring entities or related commercial locations at points of sale including the
Internet; other commercial and non-commercial purposes.
[0031] The following are merely illustrative of some of the uses, advantages and objects
which the new system provides: television advertising response determination; interactive
advertising and promotions; attracting of viewers' attention; effectively increasing
consumer awareness and retention of commercial advertising, messages, announcements,
promotions, and specific products and services; increasing customer differentiation
of products and services; stimulating viewers to watch commercials; increasing store
traffic in response to commercial messages; fostering consumer loyalty; enhancing
viewer involvement in program content, including commercials; enhancement of viewer
retention of the content of commercial and other messages; enhancing value of commercial
messages; increased product/service sales; saving advertising costs; acceleration
of response time of customers following delivery of commercial messages; verifying
contests and awards; enhancing viewer retention of the related website domain names;
reducing of barriers related to e-commerce opportunities; providing additional and
sometimes instant rewards and information obtainable via the Internet.
[0032] When carrier signals are detected by use of the decoder, various signals, indications,
display readouts, or other interactive events provide the user with a benefit. The
various interactive events described in Koplar I, Koplar II, Withers and Barsoum are
usable interchangeably by and in conjunction with the hand-held device and methods
of use with the present invention. The interchangeability includes selective use of
the features of the present invention, along with selective use of any of the various
apparatus and methods of Koplar I, Koplar II, Withers and Barsoum.
[0033] The uses, objects and advantages of the invention are more fully developed in the
following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034]
Fig. 1 is a first flow chart of the encoding method of the present invention.
Fig. 2 is first a flow chart of the decoding method of the present invention.
Fig. 3 is a block diagram of the encoder of the present invention.
Fig. 4 is a block diagram of a decoder of the present invention.
Fig. 5 is a block diagram of a combo user device of the present invention.
Fig. 6 is a second flow chart of the encoding method of the present invention.
Fig. 7 is a frame timing and value diagram of one embodiment of the present invention.
Fig. 8 is a second flow chart of the encoding method of the present invention.
Fig. 9 is a frame timing and value diagram of one embodiment of the present invention.
Fig. 10 is a frame timing and value diagram of one embodiment of the present invention.
Fig. 11 is a second flow chart of the decoding method of the present invention.
Fig. 12 is a third flow chart of the decoding method of the present invention.
Fig. 13 is a flow chart of the game playing method of the present invention.
[0035] Corresponding reference characters indicate corresponding elements among the several
views.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Referring to the drawings, the preferred embodiment of a method of encoding a carrier
signal within a video signal presented by a digital display device is illustrated
in Figs. 1-13.
[0037] Referring to Fig. 1, a video program in the form of video signal 18 is transmitted
from a signal source 10 to an encoder 12. Video signal 18 is preferably a digital
video signal, but may be other video signals or video signal formats compatible with
the present invention. Video signal 18 may either be in analog or digital form, as
encoder 12 handles either signal via analog signal input 32 and digital signal input
30 as described in greater detail below. The preferred format for a digital video
signal under the present invention is the serial digital interface (SDI), the technical
standard of which is maintained by the Society of Motion Picture and Television Engineers
(SMPTE) as SMPTE 259M. SDI at the time of the invention is the standardized protocol
for sending video information in a digital bit stream.
[0038] Signal source 10 is typically a high definition digital video source such as a high
definition television broadcast station, but may also be other sources of video signals
including a professional grade video tape player with a video tape containing a video
program, camcorder or a digital versatile disc (DVD) player with a DVD video containing
a video program. Encoder 12 is described in further detail in the description of Fig.
3 below.
[0039] Operator 16 interacts with encoder 12 to control operation of encoder 12. Preferably,
operator 16 is a person that interacts with encoder 12 through the use of a computer
or other electronic control device as will be described in greater detail below. However,
operator 16 may consist entirely of a computer or other electronic control device
that directs operation of encoder 12 in an automated manner.
[0040] A carrier signal 20 is selectively encoded in video signal 18 by encoder 12 over
one or more sets of two frames of video signal 18 for a time interval by operator
16 for signaling purposes, such as to embed signal presences and signal absences in
video signal 18 over desired intervals. Upon modulating video signal'18, encoder 12
outputs a modulated video signal 22 comprised of video signal 18 and carrier signal
20.
[0041] Modulated video signal 22 is then provided to a broadcast source 14 for dissemination
or distribution to one or more end-users who view the video program. Broadcast source
14 is preferably a high definition television broadcast source, but also may be other
media sources including video tapes, DVD media or other digital storage media that
will be provided to one or more end users, television broadcast stations, cable or
satellite sources or wireless sources that broadcast programs.
[0042] Referring to Fig. 2, broadcast source 14 provides modulated video signal 22 to a
decoder 13, which passes modulated video signal 22 through to digital display device
26 unaltered. Digital display device 26 differs from a standard analog display device
in that digital display device 26 is an active display such that each of its pixels
illuminate at the same time, instead of when they are struck by an electron beam from
a CRT tube. Additionally, the pixels of digital display device 26 are instant on/instant
off and do not retain any trace of video signal 18. In contrast, analog display devices
have a p-factor of 4 in retaining video signal 18. It should also be understood that
digital display device 26 may alternatively be a digital video recorder and other
devices capable of digitally presenting or recording video signals.
[0043] As discussed in greater detail below, decoder 13 uses modulated video signal 22 to
determine whether a carrier signal 20 is present in modulated video signal 22 over
a specified or predetermined time interval so as to trigger a signal absence (e.g.,
carrier signal 20 not present in video signal 18) or signal presences (e.g., carrier
signal 20 present in video signal 18) of carrier signal 20. Decoder 13 is suitably
configured and connected to broadcast source 14 to receive modulated video signal
22 and detect carrier signal 20 therefrom. When carrier signal 20 is present, decoder
13 provides notification of the signal presence of carrier signal 20 to a signaled
device 24 by transmission of transmission signal 21. When carrier signal 20 is not
present, decoder 13 transmits a signal absence. Signaled device 24 is preferably any
device that is capable of receiving and utilizing one or more signal absences and
signal presences. Preferably, transmission signal 21 is a wireless radio frequency
signal, but it should be understood that other types of signals including infrared
are felt to fall within the scope of the present invention.
[0044] Preferably, signaled device 24 and decoder 13 are combined together in a combo user
device 15 such as a hand-held device that considers the signal presence to be a data
bit of "1" and the signal absence a data bit of "0" and uses the data bits to provide
promotional opportunities to its user. Combo user device 15 does not send or receive
transmission signal 21, but rather receives video signal 18 optically directly from
digital display device 26 and is described in greater detail below.
[0045] Referring to Fig. 3, encoder 12 is shown in greater detail to first include encoder
micro-controller 36, which may consist of more than one processor to manage the various
processing and input/output of the present invention, and preferably consists of a
second processor in the form of a digital signal processor 54. Digital signal processor
54 assists encoder microcontroller 36 with processing signal and other information
of encoder 12, including modulating carrier signal 20 in video signal 18. It should
be appreciated that encoder 12 may comprise varying degrees of hardware and software,
as various components may interchangeably be used as either. Moreover, the specific
electronics and software used by encoder 12 may differ when its technology is included
in a pre-existing device as opposed to a stand-alone device.
[0046] Encoder 12 further comprises a digital video input 30 that is electronically coupled
to encoder micro-controller 36 and capable of receiving video signal 18 from signal
source 10 and passing it to encoder micro-controller 36. However, encoder 12 may receive
an analog video signal 18 via analog video input 32 and analog to digital converter
34. Analog to digital converter 34 digitizes the analog video signal 18 according
to known techniques such that it may be digitally provided to encoder micro-controller
36.
[0047] Encoder micro-controller 36 is electronically connected to a carrier presence 38,
which provides encoder micro-controller 36 with the timing of where, when and at what
intensity encoder 12 should selectively alter the intensity of the pixels of a frame
of video signal 18 or portions thereof at the direction of operator 16. Preferably,
such instructions are received by carrier presence 38 via a serial port. However it
should appreciated in the art of computer hardware that other device interconnects
of encoder 12 are contemplated for carrier presence 38 including via universal serial
bus (USB), "Firewire" protocol (IEEE 1394), and various wireless protocols. In an
alternate embodiment, carrier presence 38 may be an operator interface so that operator
16 can directly interface with encoder 12.
[0048] When encoder micro-controller 36 receives video signal 18 and instructions from carrier
presence 38, encoder micro-controller 36 directs encoder software 50 to store the
chrominance information (and/or luminance information as desired) of video signal
18 in storage 40 from which it split off by use of a comb filter of encoder electronics
42. Encoder electronics 42 at the direction of encoder micro-controller 36 selectively
uses the present invention and (optionally in conjunction the methods of Broughton
and/or its improvements as desired) to increase and decrease the intensity of the
pixels of the frames of video signal 18 thereby creating modulated video signal 22.
The luminance of video signal 18 is then reassembled with the chrominance to provide
a complete modulated video signal 22. The resulting modulated video signal 22 is then
sent digitally from encoder 12 by digital video output 44, or in analog form by converting
the resulting digital signal with digital to analog converter 46 and outputting modulated
video signal 22 by analog video output 48.
[0049] Preferably, an SMPTE time code 56 is present on encoder 12 and electronically coupled
to encoder microcontroller 36. SMPTE time code 56 enables encoder 12 to encode carrier
signal 20 at predetermined portions of video signal 18 by use of a similar SMPTE code
on the source of carrier presence 38, instead of a person such as operator 16 manually
directing the encoding of carrier signal 20.
[0050] Referring to Fig. 4, decoder 13 receives modulated video signal 22 from broadcast
source 14 by analog video input 32 when modulated video signal 22 is analog, and by
digital video input 30 when modulated video signal 22 is digital. Digital video input
30 directly passes modulated video signal 22 to decoder processor 60, while analog
video input 32 rectifies and digitizes modulated video signal 22 by use of analog
to digital converter 34 before passing modulated video signal 22 to decoder processor
60.
[0051] Preferably, decoder processor 60 stores the luminance of modulated video signal 22
in memory (not shown) or storage 40 while decoder electronics 62 detects frames of
modulated video signal 22 that have increased or decreased intensity. The preferred
embodiment of the detection scheme used with decoder 13 is described below.
[0052] Transmission signal 21 is outputted from decoder 13 by carrier indicator 68 so as
to notify signaled device 24 of the detection of signal absences or signal presences.
Decoder 13 also outputs modulated video signal 22 in digital format via digital video
output 44, or modulated video signal 22 in analog format by first converting signal
22 from the digital to analog format by use of digital to analog converter 46, and
then outputting signal 22 via analog video output 48.
[0053] The combination of decoder 13 with signaled device 24 is shown as combo user device
15 in Fig. 5, and is the preferred device for detection of carrier signal 20. Combo
user device 15 includes many of the components of signaled device 24 and also includes
decoding processor 60 and storage 40 which function as previously disclosed above.
Combo user device 15 further comprises photodetector 70, which is electronically coupled
to decoder processor 60 and capable of optically receiving video signal 18 directly
from digital display device 26.
[0054] Electronically coupled to decoder processor 60 are pre-amplifier 78 and gain controls
76, which together amplify video signal 18 by changing the resistance on a feedback
circuit. Decoder processor 60 controls the amount of gain provided to the circuit.
Pre-amplifier 78 and gain controls 76 are used with combo user device 15 as the distance
and intensities received from digital display device 26 may vary. Accordingly, when
the strength of video signal 18 is low, it is desirable to add gain so that a better
reading of video signal 18 is possible. Hence, the present invention measures the
signal strength and decides whether to lower or increase the gain.
[0055] Analog filters 72 are electronically coupled to decoder processor 60 and provide
a low pass filter that removes the high frequency noise from video signal 18 by eliminating
all frequencies above a preset level and cleans the signal below a frequency by discarding
the undesired signal. Preferably, analog filters 72 are set for 15 Hertz center frequency
so as to filter the video energy captured by means of the photodetector 70 (i.e.,
so that it will detect the A/C nature of the 15 Hertz signal).
[0056] Integrator 74 is electronically coupled to decoder processor 60 and detects and measures
video signal 18 for one complete frame. Thereafter, analog to digital converter 34
measures the signal strength result of the frame to determine whether carrier signal
20 was present in the particular frame of video signal 18. Optional user indicator
80 provides a means to provide user of combo user device 15 with notice of availability
of promotional opportunities based on the receipt of one or more signal absences or
signal presences.
[0057] Other components may also optionally be added to combo user device 15. Computer interface
port (not shown) may be included with the present invention to redeem promotional
opportunities such as by the use of a computer with Internet access. It should be
further appreciated that photodetector 70, preamplifier 78, gain controls 80, analog
filters 82, integrator 74, and analog to digital converter 76 may be implemented on
a SD card (as described in Barsoum) that is inserted in a version of a hand-held device
that also includes the provision of a SD card slot (not shown). Combo user device
15 may also selectively include the features of the hand-held devices disclosed in
Koplar I, Koplar II, Withers or Barsoum.
[0058] Referring to Fig. 6, the preferred method of modulating carrier signal 20 within
video signal 18 by an encoder 12 comprises a first step 100 where video signal 18
is generated in real time or pre-recorded at signal source 10. Thereafter, at step
102, video signal 18 is provided to encoder 12 from signal source 10 by either digital
video input 30 or analog video input 32, depending on whether video signal 18 is in
digital or analog form. If video signal 18 is analog, analog to digital converter
34 digitizes video signal 18 by creating a digitized video signal 18 by splitting
it into its component luminance (i.e., intensity) and chrominance values. Digital
signals are already broken into their component luminance and chrominance values and
therefore no further processing of video signal 18 is needed. Accordingly, if video
signal 18 is digital, then it is already a digitized video signal 18 and no processing
is necessary prior to providing video signal 18 to encoder microcontroller 36.
[0059] Encoder 12 at step 104 stores the chrominance value of the digitized video signal
18 in storage 40. In the preferred embodiment, the chrominance value of video signal
18 is unaltered during the encoding process. Encoder 12 also stores the luminance
value of the digitized video signal 18 in encoder memory 52.
[0060] Operator 16 at step 106 directs encoder 12 through various indications received by
encoder 12 through carrier presence 38 on the inclusion of signal presences and signal
absences in selected pairs of frames of video signal 18. When operator 16 provides
a text message to the user of decoder 13 or combo user device 15 by use of carrier
signal 20, operator 16 preferably enters a message into a computer source that converts
the textual information into the proper string of signal presences (i.e., ones) and
signal absences (i.e., zeros) in either real time or at a time set by use of the SMPTE
time code 38. The message is then passed from operator 16 to encoder 12 by carrier
presence 38.
[0061] Upon receipt of the indications from operator 16, encoder 12 at decision point 108
first determines the timing of where the fields of the frames of video signal 18 start
by use of the vertical synchronization signal ("vertical sync"). Encoder 12 determines
the timing of the vertical sync by obtaining the information during the inputting
process. Preferably, a digital line obtains the vertical sync information from the
analog to digital converter 34 while performing the digitization. Not only does analog
to digital converter 34 split video signal 18 into its digital components, but it
also sends a data line of high when it receives a vertical sync. Accordingly, by obtaining
the aforementioned information, encoder 12 determines the start of the fields so as
to determine the proper place to begin encoding.
[0062] Encoder 12 thereafter at decision point 108 determines whether to encode a signal
absence or signal presence based on the indication received through carrier presence
38. In a first and preferred embodiment as shown in Fig. 6, if encoder 12 does not
receive any instructions via carrier presence 38 to modify video signal 14, encoder
12 at step 114 continuously encodes signal absences, such that the luminance value
of two consecutive frames of video signal 18 is not modified and there is no detectable
carrier signal 20 within video signal 18 during these frames.
[0063] However, when at decision point 108 encoder 12 seeks to encode a signal presence,
during steps 110 and 112 encoder 12 modifies the luminance of two frames of video
signal 18 so as to modulate video signal 18. The present invention varies the luminance
of the entire frame of video signal 18 rather than varying it line by line as is Broughton.
At step 110, the luminance of the first frame of video signal 18 is increased by a
slight amount, such as 50-70 mV. Thereafter, at step 112 the luminance of the second
frame of video signal 18 is decreased by a slight amount. The encoder 12 thus by raising
and lowering the luminance of two consecutive frames creates a frequency of 15 Hertz.
[0064] The encoding of a signal presence results in modulated video signal 22 with an alternating
characteristic not detectable by the human retina but detectable by an optical detector,
photo diode, or photodetector (collectively referred to hereinafter as a "photodetector
70") or by electrical detection means. Therefore, by modulating video signal 18 with
a series of signal presences and signal absences over a period of time, a data string
may be encoded and detected by detector 13 and transmitted to signaled device 24 or
transmitted from a digital display device 26 and optically detected directly by combo
user device 15.
[0065] The encoding of the present invention during steps 110, 112 and 114 is on a frame
by frame basis, as the present method encodes for a complete frame (i.e., two fields).
Since the two fields are not necessarily interlaced (i.e., they could be a progressive
scan), the entire frame may be displayed all at one time. Accordingly, encoding over
two fields necessitates use of a complete frame. Thus, the present invention synchronizes
encoding to the first field of the frame and not the second field since the circuitry
does not determine the method of display of the second field. However, the present
encoding methods relies on encoding frames in sets of two so as to compare the relative
luminous value of the frames to determine whether there has been intensity added to
or subtracted from the frames. Since adjacent frames typically have nearly the same
intensity, modifications to the intensity are detectable by a decoder 13 or combo
user device 15.
[0066] During steps 110 and 112, encoder 12 adds or subtracts from the level of luminance
of particular pixels in video signal 18. In general, luminance varies from zero to
maximum scale value of 100, with a bright screen at 100 and a dark screen at zero.
Encoder 12 modulates the luminance around whatever value is obtained. By use of the
steps 110 and 112, varied with the step 114, the method effectively creates an AC
signal that rides on top of the DC energy being produced by video signal 18.
[0067] Once video signal 18 is encoded with a signal absence or signal presence pursuant
to step 110 and 112 or 114, it is outputted from encoder 12 as modulated video signal
22 by digital video output 44. If modulated video signal 22 is to be outputted as
an analog signal, signal 22 is converted to analog by digital to analog converter
32 and outputted by analog video output 48.
[0068] As shown in Fig. 7, a demonstration of the foregoing method of encoding of carrier
signal 20 in video signal 18 includes a sine-wave demonstrating a 15 Hertz signal
during the first four frames and no 15 Hertz signal presenting during the last two
frames representing signal presence, signal presence and signal absence respectively.
[0069] A second encoding method of the present invention is shown in Fig. 8 to comprise
the same steps 100, 102, 104, and 106 of the preferred encoding method described above.
After completing the aforementioned steps, encoder 12 at decision point 160 determines
the timing of where the fields start by vertical sync as describedabove. Thereafter,
encoder 12 modulates a constant sine wave in every frame of video signal 18 and determines
whether to encode a signal absence or signal presence in video signal 18.
[0070] If encoder 12 is to encode a signal presence, then encoder at steps 162, 164 first
increases and then decreases the amplitude of the sine wave in respective frames.
In contrast, if encoder 12 is to encode a signal absence, then encoder at steps 166,
168 first decreases and then increases the amplitude of the sine wave in respective
frames. Accordingly, the complementary encoding of "decrease increase" represents
a signal absence, and the complementary encoding of "increase decrease" represents
a signal presence. It should also be appreciated that the reverse of the "increase
decrease" patterns could also be used as desired.
[0071] As shown in Fig. 9, a demonstration of the foregoing method of encoding of carrier
signal 20 in video signal 18 includes a sine-wave demonstrating encoding of "decrease
increase", "increase decrease" and "decrease increase" during six frames of video
signal 18 representing signal absence, signal presence, and signal presence respectively.
[0072] In yet another embodiment, a third encoding method of the present invention comprises
the same steps 100, 102, 104, and 106 of the preferred encoding method described above.
After completing the aforementioned steps, encoder 12 at decision point determines
the timing of where the fields start by vertical sync as describe above.
[0073] Encoder 12 modulates a constant 15 Hertz signal sine wave in every frame of video
signal 18 and determines whether to encode a signal absence or signal presence in
video signal 18. Encoder 12 adds one or more amplitude levels to the amplitude of
video signal 18 on a frame by frame basis, for which the resulting reception of such
video signal 18 will generate a code relative to one or more data bits. Preferably,
two amplitude levels are available for each frame so that each frame may then encode
a single bit. Accordingly, by use of this embodiment, two consecutive frames may be
used to encode two complimentary bits.
[0074] Fig. 10 provides an example of the aforementioned method of encoding of two consecutive
frames of 2x and -1x, 1x and -1x, and 2x and -2x, which respectively correspond to
bit codes of "10", "00" and "11".
[0075] The present encoding methods preferably do not modify the audio signal that is part
of video signal 18, as the audio signal passes directly through encoder 12 unaltered.
The delay between the audio and video is minimal (i.e., only one or two lines) which
may result in a 50 microseconds delay per line. Since this delay is generally not
perceivable for a person viewing the video program on digital display device 26, it
is preferably not necessary to delay the audio at encoder 12. However, if necessary
or desirable, encoder 12 may also include audio delay circuitry to ensure that the
audio and video are in perfect synchronization.
[0076] Once the modifications to video signal 18 are complete, encoder 12 outputs the resulting
modulated video signal 22 via digital video output 44 or analog video output 48 though
digital to analog converter 46. Modulated video signal 22 is then provided to broadcast
source 14 so that it may be presented on digital display device 26.
[0077] As an alternative to the foregoing encoding methods, encoder 12 may make the luminance
changes within a line instead of by frame. Thus, instead of encoder 12 outputting
an entire line of luminance to broadcast source 14, the changes are made to video
signal 18 as it enters encoder 12 instead of by storing it.
[0078] Referring to Fig. 11, at step 120 combo user device 15 optically detects modulated
video signal 22 from digital display device 26 by a photodetector 70. When using decoder
13, broadcast source 14 at step 120 provides modulated video signal 22 to decoder
13 for detection. Decoder 13 provides unaltered modulated video signal 22 to digital
display device 26 for presentation to a viewer of the video program presented on digital
display device 26 and also uses modulates signal 22 on decoder 13 as described for
combo user device 15 in greater detail below.
[0079] Combo user device 15 (or decoder 13) at step 122 amplifies and filters modulated
video signal 22. Thereafter, at step 124 combo user device 15 integrates modulated
video signal 22 for one complete frame. Once the signal is integrated, at step 126
analog to digital converter 34 measures the signal strength of modulated video signal
22. Thereafter, decoder processor 60 at step 128 decodes signal absences or signal
presences by comparing two consecutive frames of modulated video signal 22 to determine
relative signal strength. If the frames have nearly the same level of signal strength
or otherwise meet the criteria for a signal absence, then combo user device 15 reports
a signal absence for the two frame set. If the frames have a differing level of signal
strength beyond a minimal threshold or otherwise meet the criteria for a signal presence,
then combo user device 15 reports a signal presence for the two frame set.
[0080] Referring to Fig. 12, at step 130 the modulated video signal 22 that was encoded
by one of the foregoing encoding methods and presented on digital display device 26
is presented and detected by combo user device 15 (or decoder 13). Thereafter, at
step 132, modulated video signal 14m is amplified and filtered by pre-amplifier 78,
gain controls 80 and analog filters 82.
[0081] Combo user device 15 at step 132 amplifies and filters modulated video signal 22.
Thereafter, at step 134 combo user device 15 integrates modulated video signal 22
for one complete frame. Once the signal is integrated, at step 136 analog to digital
converter 34 measures the signal strength of modulated video signal 22.
[0082] Thereafter, decoder processor 60 at decision point 138 determines whether combo user
device 15 was looking at the first or second of two frames. If decoder processor 60
was looking at the first frame, decoder processor 60 returns to step 130 to detect
the second frame of video signal 18. If not, decoder processor at step 140 decodes
a data bit of 0 (i.e., a signal absence) or 1 (i.e,. a signal presence) in modulated
video signal 22, or in the case of the third encoding method two data bits.
[0083] At step 142, decoder processor 60 determines whether there are more bits of data
remaining in the transmitted packet of data. If yes, decoder process 60 returns to
step 130 to detect additional data bits. If no, decoder processor 60 at step 144 determines
whether the data packet passes a CRC test. If no, decoder processor 60 discards the
data packet and returns to step 130.
[0084] If yes, decoder processor 60 proceeds to decision point 146 where it determines whether
the data packet it received is the end of the message (i.e., the last of a series
of packets). If no, decoder processor 60 returns to step 130 to receive additional
data packets to complete the message. If yes, decoder processor at step 148 proceeds
to provide the message and/or promotional opportunities to the user of combo user
device 15.
EXAMPLE
[0085] A practical embodiment of the foregoing may be observed in Fig. 13 to comprise a
first step 160 at which digital display device 26 such as a plasma television presents
a video program such as cartoon to a user of combo user device 15. Video signals 18
of the cartoon are modulated with carrier signals 20 in accordance with one of the
embodiments of the present invention and are transmitted from broadcast source 14
to the plasma television.
[0086] At step 162 viewer watches the cartoon with combo user device 15. Next, at step 164
the user orients combo user device 15 , in the form of a game device 15 such as a
"Nintendo Gameboy", towards the plasma television. The user configures and then preferably
begins playing a video game on game device 15. Game device 15 is outfitted with an
optical detector, circuitry and appropriate software to optically receive video signals
18 from digital display device 26.
[0087] During the course of the video game on game device 15, the cartoon transmits modulated
video signals 22 to game device 15. Viewer at step 166 receives modulated video signals
22 on game device 15. Game device 15 thereafter detects carrier signal 20 so that
game device 15 can receive enhanced play, such as additional lives, bonus levels,
new weapons, new monsters, etc. by detection of carrier signals 20 on the hand-held
device. Viewer at step 168 can take advantage of the enhanced play from the detection
of carrier signals 20.
[0088] It should also be appreciated that the present system also permits coexistence with
other modulation and encoding schemes such as described in Broughton. Accordingly,
by the use of Broughton and the present invention, both analog and digital display
devices may broadcast auxiliary data that can be received by hand held devices outfitted
to receive these video signals.
1. A method for encoding a signal presence within a video signal to be presented on a
digital display device, the video signal having a first frame and a second frame,
the first frame and the second frame each comprised of a plurality of pixels, the
method comprising:
obtaining the video signal from a signal source and providing the video signal to
an encoder;
selectively altering luminance of the pixels of the first frame and the second frame
of the video signal to represent the signal presence; and
providing the video signal with altered luminance to a broadcast source.
2. The method of claim 1 wherein the step of selectively altering luminance is by creating
a significant difference in signal strength between the first frame and the second
frame of the video signal.
3. The method of claim 1 wherein the step of selectively altering luminance is triggered
by receipt of a carrier signal.
4. The method of claim 1 wherein the step of selectively altering luminance of the first
frame and the second frame of the video signal to represent the signal presence is
by increasing overall luminance on the first frame of the video signal and decreasing
overall luminance on the second frame of the video signal.
5. The method of claim 1 wherein the step of selectively altering luminance of the first
frame and the second frame of the video signal is by adding a sine wave signal to
the video signal and increasing the amplitude of the sine wave signal in the first
frame of the video signal and decreasing the amplitude of the sine wave signal in
the second frame of the video signal.
6. The method of claim 1 wherein the step of altering luminance of the first frame and
the second frame of the video signal is by adding a sine wave signal to the video
signal and setting the amplitude of the sine wave signal to one of two signal levels
in the first frame of the video signal and independently setting the amplitude of
the sine wave signal to one of two signal levels in the second frame of the video
signal.
7. A method of detecting signal absences and signal presences in a video signal, the
video signal having a first frame and a second frame, the method comprising:
receiving the video signal from a broadcast source on a detector;
performing on the detector a comparison of signal strength of the first frame of the
video signal with signal strength of the second frame of the video signal;
providing the detector with a signal absence if the comparison is negligible; and
providing the detector with a signal presence if the comparison is not negligible.
8. The method of claim 7 wherein the detector is a combo user device.
9. The method of claim 7 wherein the signal absence is a data bit of 0 and the signal
presence is a data bit of 1.
10. A game device for use by a user in conjunction with a video signal representing a
video program, the device comprising:
a device microcontroller;
a means for detecting the carrier signal in the video signal on the game device and
electronically coupled to the device microcontroller; and
a means for receiving additional game options on the gaming device from detection
of the carrier signal on the game device and electronically coupled to the device
microcontroller.
11. The game device of claim 10 wherein the means for detecting the carrier signal in
the video signal on the game device is a photodetector and accompanying circuitry.
12. A system for transmitting a modulated video signal to be presented on a digital display
device, the video signal having a first frame and a second frame, the first frame
and the second frame each comprised of a plurality of pixels, the system comprising:
a signal source for generating a video signal;
an encoder, the encoder comprising a means for receiving the video signal from the
signal source; a means for selectively altering luminance of the pixels of the first
frame and the second frame of the video signal to represent a signal presence or signal
absence and thereby creating a modulated video signal; and a means for providing the
modulated video signal to a broadcast source; and
the broadcast source for providing the modulated video signal from the encoder to
a digital display device.
13. The system of claim 12 further comprising a decoder, the decoder comprising a means
for receiving the modulated video signal from the broadcast source; a means for performing
on the detector a comparison of signal strength of the first frame of the video signal
with signal strength of the second frame of the video signal; a means for providing
the detector with the signal absence if the comparison is negligible; and a means
for providing the detector with the signal presence if the comparison is not negligible.
14. The system of claim 12 wherein the decoder contains means to provide the signal absence
or the signal presence to a signaled device.
15. The system of claim 12 where the means for receiving the modulated video signal from
the broadcast source is a photodetector and accompanying circuitry.
16. The system of claim 12 wherein the means for selectively altering luminance is by
creating a significant difference in signal strength between the first frame and the
second frame of the video signal.
17. The system of claim 12 wherein the means for selectively altering luminance is triggered
by receipt of a carrier signal.
18. The system of claim 12 wherein the means for selectively altering luminance of the
first frame and the second frame of the video signal to represent the signal presence
is by increasing overall luminance on the first frame of the video signal and decreasing
overall luminance on the second frame of the video signal.
19. The system of claim 12 wherein the means for selectively altering luminance of the
first frame and the second frame of the video signal is by adding a sine wave signal
to the video signal and increasing the amplitude of the sine wave signal in the first
frame of the video signal and decreasing the amplitude of the sine wave signal in
the second frame of the video signal.
20. The system of claim 12 wherein the means for altering luminance of the first frame
and the second frame of the video signal is by adding a sine wave signal to the video
signal and setting the amplitude of the sine wave signal to one of two signal levels
in the first frame of the video signal and independently setting the amplitude of
the sine wave signal to one of two signal levels in the second frame of the video
signal.
21. The system of claim 13 wherein the signal absence is a data bit of 0 and the signal
presence is a data bit of 1.